The diary has been widely discussed for over a year. There is nothing new here.
Maybe it was widely discussed but I never heard of it until the FBI raids. If it was over a year old story, why have the FBI dredge it up now? It makes no sense at all. They just made more people aware of it and gave it an air of legitimacy.
I can’t know the real motives, but the surface story of “oh the FBI is acting like Biden’s private Stasi” may ring true but it could also be the opposite. Blackmail, coercion, etc against the President.